Stoker control



Aug. 24, 1937. C, A, WAR@ 2,091,192

STOKER CONTROL A5 VLM "um mmm Marla/4. H/arj c. A. wARG STOKER CONTROLAng. 24, 1937.

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7 Sheets-Sheet 5 c. A. WAR-G STOKER CONTROL Filed July 29, 1932 Aug. 24,1937.

ug."24, 1937. Q A- WARG 2,091,192

STOKER CONTROL Filed July 29, 1932 7 Sheets-Sheet 4 :E i: zmz

C. A. WARG STOKER CONTROL Aug. 24, 1937.

Filed .Iuly 29, 1952 v 7 Sheets-Sheet 5 Charles/4. Wag

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Aug. '24, 1937.

c. A. wARG 2,091,192

STOKER CONTROL l'7 Sheets-Sheet 6 Filed July 29, 1952 W no :El: .E

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Aug. 24, 1937. c. A. wARG A STOKER CONTROL Filed July 29, 1932 7Sheets-Sheet 7` Patented Aug. 24, 1937 UNITED STATES -LPTENT OFFICESTOKER ooNTRoL Charles A. Warg, Scranton, Pa., assignor to Mc-Clave-Brooks Company, Scranton, Pa., a, corporation of PennsylvaniaApplication July 29, 1932, Serial No. 626,160

23 Claims.

i l Vturn is controlled by the steam pressure of the boiler, speeding upwhen the pressure falls and slowing down fwhen the pressure increasesbeyond a chosen gure.

Such devices as have been broadly described 15..are, of course, old andhave been in practical use for a great many years but the better typesoiier certain disadvantages and it is the principal Y `'object of thepresent invention to provide an interval control for a steam driveunderfeed stoker 0 which will be simple and reliable, of relatively lowcost, and which will secure economy of steam `highly desirable abilityto have rapid speed of operation of the ram in the steam cylinder while25 keeping the timing mechanism operating at a slow rotative speed.Inasmuch as the interval control mechanism of the present invention maybe located adjacent the ram cylinder and because of the use of thepoppet valves extremely prompt n .i the `timing unit the poppet steamadmission 30 30 cut-off is provided, this yielding maximum steameconomy.

In the. drawings: Figure 1 is a side elevation of the intervalcontrolassociated with a cam chamber and valve 35 chamber.

Figure 2 is a sectional view taken on line 2 2 of Figure 3. V.Figure 3is a vertical section looking into the .cani chamber from a plane justfree of the end 40 wall and looking at the valve chamber from the fTeal.

Figure fi is a top plan view of the cam chamj fan increases the speed offeeding the coal will ber with the cover remove-d.

Figure 5 is an end elevation of the timing unit. 45 Figure 5a is a viewof the counting pawl, set

at at the end of its stroke, having moved Y from the position shown inFigure 5.

Figure 6 is a diagram of the working pawl in position about to opensteam valve A and exhaust valve B.

Figure 7 is a similar View after three oscillations in which positionthe steam valve C and the exhaust valve D are open.

55 Figure 8 is a view similar to Figure 5a 'but which usually would beof underfeed type.

showing the counting pawl set at eight teeth whichA gives maximum speed.

Figure 9 shows the parts of Figure 8 after a single oscillation.

Figure 10 is a sectional side elevation of an 5 installation embodyingmy invention.

Figure 11 is a front elevation of such installation.

The general layout is shown in Figure 1 in which I0 is the mainoperating shaft which has 10 intermittent rotation always in the samedirection, this movement being provided by means of ratchet Wheels I I(Figure 2) and l2 fast to the shaft Il) and receiving motion thru pawlswithin fthe timing .housing I4, the latter having oscil- 15 Llatingmovement only, derived thru connecting rod I5, the far end I6 of whichis connected either directly or indirectly to a crank Il on a constantlyturning shaft I8 the speed of which l `varies inexact accord with thespeed of the fan Vblower shaft, for example, being connected to the`,consumption and floor space while giving the y latterithru, reducinggearing. Any method of .connecting the rod I5 so as to oscillate inaccordance with the speed of the fan or with fluctuations of pressure ofthe boiler may be used, many available schemes being well known and Asthe main operating shaft I0 rotates intermittently in accordance With asetting made on valvesA and.C leading to the ram and the exhaust ValvesB and D are operated in timed sequence to deliver steam alternately tothe front l Yand rear of the ram cylinder, the ram in accordance withusual practice being fast to a plunger which latter reciprocates in afuel passage fed bya hopper and pushes the coal into the furnace Theadmission valve A does not appear in the drawings but its position, asindicated in Figure 4, is

directly behind valve C in Figure 2; the valves areall preferably alike.As the blast from the likewise increase as is customary in such devices,

producing maximum efficiency of combustion 45 (see Figure 11).

Referring now particularly to the timing unit,

Figures l, 2 and 5, the housing I4 is composed of two portions, thesmaller portion being a cover I9 securedto the main body of the housingas by 50 the bolts and nuts 20, correct positioning being insured by thepins 2| vand also by the fact that the-crank arms 2I and 22 are ondifferent pieces one on the main body of the housing and the other onthe cover I9 so that incorrect assembly 55 is impossible because thebosses 23 at the end of the crank arms 2 I must aline to receive thewrist pin 24 on which the connecting rod I5 is pivoted.

The housing oscillates freely on the main shaft Il and is held laterallyin position against the body of the cam chamber by means of a collar 25held in place on a reduced portion of the shaft l by a set screw 26. Itis highly advisable to extend the shaft I0 beyond the reduced end 2 onwhich the collar is mounted in order to provide a slabbed portion 3D toreceive a hand crank 3! by which the main operating shaft I0 may bemoved at any time to chosen position for any purpose.

To the near or free side of the housing I4 and extending partly withinthe housing is a counting pawl setting arm consisting of two portionsxedly secured together, one the finger piece 33 and the other a sleeve34 loose on the shaft I0 and having a projection 35 by means of whichthe adjacent counting pawl cam 35 is driven when the setting arm movesin one direction, the engagement being with the large counterbalancingportion 38 not seen in Figure 1 but well shown in Figures 5, 8 and 9.

While the two portions of the counting pawl setting arm, namely, thenger piece 33 and the sleeve 34, normally move with the rocking housingI4 of the timing unit the setting arm has manual movement relatively tothe housing for the purpose of setting the device so as to operate atdifferent speeds, the latter being indicated by the large embossednumerals 4B on the outside of the timing unit housing or case as bestseen in Figure 5. The front or near face of the housing I4 is providedwith a plurality of spherical recesses 4i to receive a ball 42 slidingwithin a bore 43 of the counting pawl setting arm and urged against thehousing and into one of the recesses 4I by means of the spring 44, seeFigure 2. A swinging of the counting pawl setting arm 33, 34 withrespect to the numerals 4U on the iace of the housing determines thenumber of teeth that are engaged at each reciprocation of the connectingrod I5 and housing I 4 as will be explained more fully later.

The counting pawl cam S is an angular piece consisting of the segmentalshaped counterbalance 3S and a radial arm 45, the latter carrying a bolt43 on which is pivotally mounted the counting pawl i? which is held bygravity against the adjacent counting disk I2 directly beneath. The pawlpivot 46 is urged to uppermost position by means of the gravity actionof the counterbalance 38. On the pivoting bolt 46 carried at the freeupper end of the arm 45 of the counterbaiance counting pawl cam 3S is abuffer 49 which is engaged at times by the counting pawl driving boss 55which latter always moves with the casing I4 and is preferably a rolleraltho it may be an integral boss. The counting pawl cam swings freely onthe main shaft I0 and is held in position laterally by engagement withthe counting disk i2 on the right and the sleeve 34 of the counting pawlsetting arm on the left. The projection 35 has a flat face 5I whichengages the flat face 52 of the counterbalance 38 as will be seen moreclearly upon ldetailed description of the pawl functions.

Adjacent the cover I9 of the timing unit housing is the operating disk II previously mentioned. This disk i I is keyed to the main operatingshaft IQ and consequently moves at all times with the counting disk I2adjacent on the left but is preferably spaced from it an appreciabledistance by the washer 55. This operating disk II can best be seen inelevation in Figures 6 and 7 particularly in relation to the workingpawl 5'! which operates it. The working pawl is shown in dotted lines inFigure 5 at the left being pivoted on a countersunk stud 58 having a nut59 (shown in Figure l) on the outside of the cover. The working pawl 57therefore constantly oscillates with the boss 5i) which engages thecounting pawl buffer 49 and with the projection 35 on the counting pawlsetting arm which latter, however, can manually be made to moverelatively to these other members. However, for any one setting, theparts just mentioned all move together and their movement is oscillatingonly, all moving with the timing unit housing I4.

t might be well at this time to describe the operation of thisparticular portion of the device, rst assuming that the counting pawlhas been set at four teeth as shown in Figure 5. The finger 33 isVertical and overlies the numeral 4 embossed on the case to indicatefour teeth at each pass of the counting pawl. The oppositely disposedprojection 35 is consequently directly beneath the embossed numeral 4and is directly below the axis of the main shaft IE). This position ofthe projection 35 prevents the counterbalance 38 from dropping to itsnormal position as in Figure 5a, and consequently holds the countingpawl buffer 49 slightly to the left of the vertical center line. At suchtime the pawl driving boss 5i) is at the extreme left as seen in Figure5 and will have lost motion until this boss 55 engages the buffer 45which is held on the pin 48 at the end of the counting pawl cam by meansof a cotter 6I.

The swing of the timing unit case is invariably ninety-ve degrees, thisallowing a right angle of ratchet travel plus an overthrow of fivedegrees. The pawl driving boss invariably moves this full ninety-fivedegrees both forwardly and backwardly. In moving from the position shownin Figure 5 to the position shown in Figure 5@ the wrist pin 24 of theconnecting rod I5 moves the full ninety-five degrees as does the pawldriving boss 55, but the latter, however, has lost motion for half ofits travel, that up to the time it engages the buffer 49 on the countingpawl cam. The last half of the movement with the driving boss inengagement with the buffer carries the counting pawl 47 forward fourteeth, this pawl being on the same pivoting bolt as is the buffer 49.This i'novement also carries the counting pawl setting arm 33, 34 fromvertical to horizontal and its projection 35 will, therefore, be seen atthe extreme left and entirely out of engagement with the flat side 52 ofthe counterbalance 38 giving a lost motion on the return of the wristpin 24, that is, on the return oscillation of the timing unit housing.The stopping point, denoted by the dot and dash line 5U, is the same forall settings and for both pawls 4i and 5? but the angular position ofthe axis of the buffer 49 varies With the setting of the arm 33.

In Figures 8 and 9 the setting is made for eight teeth instead of four,the travel under such circumstances being maximum as is the speed of theshaft I3, and the pawl driving boss 5U is consequently always in contactwith the buffer 49 as these two parts on `travel either forward andrearward oscillate together, there being no lost motion of any kind andthe .flat face 5I o1" the setting arm 33, 34 and the corresponding fiatface 52 of the counterbalance of the counting pawl cam 36 are likewisein constant engagement. The beginning of the movement is shown in Figure8 and the end of the movement is shown in Figure 9 from which latterfigure it will be noted that the parts i9 and 58 are in just the samerelative positions as in Figure 52L but the setting arm in Figure 5a ishorizontal allowing for the lost motion on return whereas there is nolost motion in Figure 9.

10 Referring now particularly to Figure 6, the operating disk Il isshown in such position that one of the steam valves (A) (see also Figure4) is about to open as is the exhaust valve corresponding to the othersteam valve (C). The

working pawl 51, as will be remembered, is mounted on a stud 58 carriedby the timing unit housing and the disk ll is keyed to the shaft iii,consequently as the housing moves in its oscillation of ninety-fivedegrees, the working pawl 51 will engage the rst tooth 62; the first vedegrees of travel being taken up by the overthrow and the remainingright angle rotating the operating disk il and with it the main shaftit, the latter causing the simultaneous opening of the steam valve A andthe exhaust valve B.

In Figure '1 the working pawl pivot 58 has moved thru two forward, i.e., clockwise oscillations, and one return or counterclockwiseoscillation, each of ninety-live degrees. The first forward movementcarried the disk ninety degrees and opened the steam valve A and theexhaust valve B. The return reciprocation left the valves A and B'open.The next forward movement of the working pawl, which this time I engagedthe third tooth 63 and not the first tooth 82, closed the valves A and Band opened the steam valve C and the exhaust valve D both to bedescribed later. in Figure '1 the steam valve C and the exhaust valve Dare both open 4,0 but they will be closed by later movement of thecounting pawl, it being remembered that both the operating disk and thecounting disk are keyed together on the operating shaft so that bothinvariably move as a unit. The third notch or 45 tooth 63 is engagedafter the shaft lil has been rotated by the counting pawl l1 insuring acomplete cycle for each revolution of the shaft le.

The position of the shaft l@ in Figure 8 is about 180 from the positionof the shaft in Figure G, 50 the former figure showing movement of theshaft due solely to the counting pawl l1 and the counting disk I2whatever the setting. The number of oscillations of the timing unithousing I d to a single revolution of the main shaft lil, that is, 55 toa complete cycle, varies from 19 at setting No. 1, 11 at 2, 8 at 3, andso on down to four oscillations for a complete cycle when set at 8. Atall settings, except at No. '1, the number of oscillations is a wholenumber but when the set- 60 ting is at 1 the oscillations will alternatefour and then five, for example beginning in Figure 6 which shows theinitial position for all settings, the first oscillation, no matter whatthe setting, will carry the first tooth 52 on the operating disk 65 tothe stopping point @d and will open Valves A and B. The second forwardreciprocation of the working pawl will bring the second tooth S4 of thecounting disk i?. to the stopping position Si) if the setting is at 8but if the setting is for 70 '1 or any smaller figure the third tooth 63of the working or operating disk Il (which is alined with the rst toothof the counting disk) is brought to stopping position, in either caseclos- 75 ing Valves A and B and opening and leaving open valves C and Dgiving the idle or return stroke of the ram of the stoker.

The next oscillation will advance the shaft I0 only thru the countingpawl 41 since from this point to the completion of the cycle the workingpawl 51 is on the largey smooth periphery of the operating disk whichhas only the three teeth whereas the counting disk has twenty-two.Valves C and D are closed about midway of this oscillation. Stillassumingthat the setting is for seven, the eighth tooth of disk l2 willbe engaged by the counting pawl and will be carried to position Si). Onthe next stroke the fifteenth tooth will be carried to the stoppingpoint and on the next stroke the twenty-first tooth, which is the lastregular tooth, will be carried to the stopping point 68. This completesthe cycle and carries the shaft l!) about beyond the initial point, soon the beginning of the next cycle the middle tooth 64 of the operatingdisk is engaged by the pawl 51, the counting pawl at this time engaginga smooth surface. Four oscillations now bring the mechanism to theinitial position shown in Figure 6.

The twenty-second tooth tl' is necessary for only one setting, and itsfunction is to prevent loss of a half stroke, it also being the desirethat the cycle shall be completed at each revolution of the shaft. Itis, therefore, possible to alter the setting at any time irrespective ofthe position of the shaft il! as upon the next few oscillations, thepawls will be brought into the initial position shown in Figure 6. Thistends to make the device quite foolproof and elli Ainates seriousdisadvantages present in other devices of the character. The zerosetting follows usual practice and prevents any movement of the ratchetwheel, the lost motion taking the entire stroke.

Considering now the cam chamber: As will be noted in Figures l, 2, and 3this chamber supports the entire device by virtue of the carrier frame18 to which are bolted the four extended legs 'li integral with thebottom. half 'l2 of the cam chamber housing. Referring particularly toFigure 2 it is seen that this bottom half has a semi-cylindricalprojecting boss and an opposite boss 15 each having therein a bushing 15to receive and guide the main operating shaft H3 which extends entirelythru the housing; the bushing 16 abuts the timing housing boss 14.

The upper half 16' of the cam housing provides the other halves of thebosses 13 and 15 and is entirely open at the top allowing for a largeone piece cover 11 held by the cap screws 18 and affording completeaccess to the mechanism within the chamber for convenient adjustment. 1twill be noted that the housing consists of two detachable sections 12and 16' separated horizontally in line with the axis of the shaft, thelower section 12 of said housing forming an oil reservoir in which thecams are emersed at each revolution of the shaft. In the Vupper half ofthe housing is mounted a bell crank shaft BQ preferably xed in positionas by the set screws 8|, This bell crank shaft 8) carries loosely fourrocking sections preferably identical but reversely arranged, each beingin the nature of a bell crank and having a pair of extending spaced lugs8l' in which are pivoted cam rollers 82 each roller being individuallyoperated by a single cam numbered 83, 86, 85 or 88 correspondingrespectively tothe steam admission valve A, the steam admission valve C,the exhaust valve D and the exhaust valve B, these cams running in A, B,D, C order counterclockwise about the shaft iii as seen in Figure 3 fromwhich figure it will be noted that the cam roller 82 when moved to theright will depress not the adjacent push rod adjusting bolt 8l shown infull lines in Figures 2 and 3 but will operate the similar bolt 8S whichis hidden in Figure 2 but shown in full lines at the left in Figure 3.The four cams are each keyed to the shaft in correct position andinaccuracy of action is further avoided by providing the holding wheelEid likewise keyed to the shaft and held against retrograde movement bymeans of a holding pawl di pivoted on a stud S2 carried by the housingand gravity operated.

Having particular reference to Figure 3 the four bell cranks each bearthe numeral 96 having in addition to the lugs Si an arm 95 threaded toreceive the push rod adjusting bolt 8'@ or Sil which after beingcorrectly adjusted is locked into position by the nut S6. Uponoscillation or a bell crank Sli by engagement of its cam as for exampleS3 with the bell crank roller E2, the push rod adjacent bolt on theopposite side descends, its domed head engaging the iiat upper portionof a push rod cap ncn-adjustably mounted the top of push rod Siti whichhas a long sliding engagement in a sleeve 99 preierably integral withthe lower half 'i2 of the chamber casing. Adjustment of the push rod issecured by means of the lower push rod cap iii which after beingpositioned correctly on the rod is locked in place by a jam nut lili.Obviously this adjustability, While helpful. is not essential as thevalve stern cap E52 at the head each seating within a valve bushing i inthe oo-dy of tf e valve chamber. The specic details of the valvemechanism form no part of the present invention and are, therefore, notdescribed in detail. Steam is admitted thru pipe Elfi passing to thesteam chamber iii in which both valves A and C open, the pipe openingdirectly beneath the latter which is the left hand valve in Figure l,the valve on the right being exhaust valve B.

The steam chamber il! opens individually t0 pipes M2 and it each leadingto the ram but on opposite ends, steam valve C admitting steam thru pipeH2 to the front of the ram cylinder for the return stroke while thecorresponding steam valve A admits steam to the rear of the raincylinder thru pipe iii for the forward or worl'ing stroke of the ram.Obviously whenever desired the pipes may be reversed and the steam valveA will then admit to the front of the cylinder thru pipe H2 for the idleor return stroke of the ram, which will then remain at the other end ofthe stroke during the idle peicd of the cycle. The exhaust chamber M5,the steam chamber, is common to the two exhaust valves B a. D and both,therefore, discharge thru pipe which preferably leads to the ash pit ofthe furnace. Valves B and C, both shown in Fi :e 2, do not operatetogether but exhaust valve D opens simultaneously with the steam valve Cas can readily be seen from the location of the cams in Figure 3 andexhaust valve B, shown in this gure, opens at the same time as steamvalve A, which in the figure is hidden by valve C.

Inasmuch as it is not at all essential that the timing unit shall belocated anywhere near the fan the valve chamber in this mechanism can beplaced as close as may be desired to the ram cylinder making the pipes li2 and i i3 very short which economizes steam consumption, causes aquick start and stop of the ram cylinder without any appreciable lagwhich lag or delay is very noticeable in other types of interval controlinechanism, and also permits as fast a movement as may be desired of theuel feeding plunger operated by the ram while still giving as slow amovement of the main shaft il? as may be desired. While 'the main shaftill might operate a rotary Valve, as is common in the prior art, thequick and positive action of the poppet valves makes the presentstructure appreciably better and I much prefer these poppet valves.

The operation of the device will be given assuming the shaft iQ to be atthe beginning of the cycle, namely, with the counting pawl driving boss56 at the lelft as seen in Figure 5, the working pawl 5l' at the angleshown in Figure G and the counting pawl il in a position which varieswith the chosen setting, i. e., the counting pawl may be under theembossed zero, 45 to the right of the center in Figure 5, or it may beunder the embossed numeral 8, forty-live degrees to the left of thecenter line. The shaft if. at such time is in such postien that the keyi i9 of the various cams is directly up and the four cams 83 to 8@ aretherefore in the positions shown in Figure 3. The first ninety degreesof movement, irrespective of the setting, turns the cam key iid thru aright angle placing it on the extreme right as seen in Figure 3. Thismovement turns the cams a quarter of a revolution, depressing theexhaust valve B and simultaneously depressing steam admission valve A,the latter admitting steam to the rear end of the ram cylinder. This isthe working stroke and causes the ram to push coal from the hopperforwardly thru the fuel passage into the retort of the stoker. Thetiming unit housing ift oscillates by rearward movement of the wrist pinZ causing no motion of the opera-L ng shaft l@ which is held byengagement of the pawl Si with the holding Wheel 9@ which is adjacentthe far boss lo. On the next forward stroke the working pawl 5l againadvances the main operating shaft lll nearly a full quarter revolutionbringing the third tooth S3 of the operating disk ii to the stoppingpoint Sii, closing valves A and B whi opening valves C and D for thestart of the return stroke of the fue] feeding rain of the Stoker. Thenext reverse oscillation of the timing unit M has no effect on the mainshait i6 but upon the following working stroke of the timing unithousing the shaft is advanced by the counting pawl 137i and countingdisk itliis action closingboththe steam admission valve C the exhaustvalve D. The ram cylinder and the coal feeding plunger therefore remainin forward position thru one or m oscillations depending upon thesetting of the counting pawi settingarm No matter iat the setting@Lexcept No. '7, the description or which has already been completed) agiven number o1 full oscillations will always bring the main operatingshaft itl to initial position shown in Figure 6, ready or the workingstroke of the fuel feeding plunger to be brought about by movement ofthe working pawl 5l, or, in case the pipes are reversed as suggested,ready for the working stroke.

In Figures and 11 I have shown an installation embodying the inventionin a somewhat 5 more compact form, the principle being exactly the same.In the particular installation shown the air duct is l2@ and the turbineblower is I2 l, the shaft l 22 of which thru a small pulley l2?, and abelt E25 drives the very much larger pulley 10 |24 on the shaft of areduction gear, the outlet shaft of which is numbered 18, being thepreviously mentioned constantly turning shaft, the speed of which variesin exact accord with the speed of the fan blower shaft. In thisparticular installation a considerable saving in space is had bymounting the units in the positions shown and keeping the unit verycompact. The turbine blower, it will be noted, is directly beneath theram cylinder lil' and the shaft |22 of the blower is extended in orderthat the pulley 23 shall be approximately directly below the pulley 24.The unit is protected with a guard |23 and it is preferable to add asheet metal plate 529 over the poppet Valve unit and 25 extending fromthe hopper it@ to the guard lfd. The particular assembly illustratedinsures the correct relation between the supply of air and the supply offuel since the forced draft blower and the poppet valve unit are bothoperated from the single steam turbine which latter in turn, being apart of the forced draft blower, is controlled automatically by a steamregulator and a balanced valve actuated by variations in the steampressure.

What I claim is:

1. In combination, a main shaft, a plurality of ratchet wheels keyed onsaid shaft, a rocker loosely mounted on said shaft, means foroscillating the rocker over a chosen arc, means cooperating with therocker and with the ratchet wheels for transmitting a chosen portion ofthe arc of motion of the rocker to said shaft to cause the shaft to turnonly in one direction and by chosen increments of rotation, a pluralityof cams on said shaft, a plurality of poppet valves and means associatedwith said cams for operati-ng all of said valves in timed sequence fromsaid cams during rotation of said shaft through an arc corresponding tothe arc of oscillation of said rocker. 2. In combination a main shaft, aplurality of ratchet wheels xedly mounted on said shaft, a housingenclosing said wheels and loosely mounted to rock on said shaft, meansfor continuously oscillating the housing over a chosen arc, meanscarried in part by the housing and in part by the shaft for transmittinga portion of the motion of the housing to the shaft to cause the shaftto turn only in one direction by chosen increments of rotation, aplurality of cams on said shaft, a plurality of poppet valves and meansfor operating said poppet valves in timed sequence from said cams.

3. The combination of claim 2 in which the housing consists of twoparts, each of which has a crank extension forming part of saidoscillating pawl engaging said counting disk, a working pawl carried bythe rocker and engaging said operating disk, means movable with saidrocker for operating said cam, and additional means carried by saidrocker and manually adjustable with respect thereto for moving said cam,a plurality of Valves for admitting fluid to and exhausting fluid fromsaid pipes, and mechanism connecting said valves to said shaft for timedoperation of said valves by movement of said rocker.

5. The device of claim 4 in which the arc of rocker oscillation is about90 and a cycle of operations of the valves is initiated with a rightangular movement of said shaft irrespective of the setting of saidmanually movable member, teeth on said operating disc cooperating withsaid working pawl to cause said right angular movement of the shaft.

6. The device of claim 4 in which the third oscillation of the rockercauses a movement of the shaft thru approximately a right angle so as toopen the valves for the return stroke irrespective of the setting of themanually movable member.

'7. The device of claim 4 in which the first oscillation of the rockerrotates the shaft thru a chosen angle opening the Valves to admit fluidto some of said pipes, the second oscillation produces no movement ofthe main shaft and the third oscillation closes the previously openedvalves and opens other valves to admit fluid to other of said pipesirrespective of the setting of the manually operated member.

8. The device of claim 4 in which the manually movable member issettable to a plurality of chosen positions each cau-sing the advance ofthe shaft thru a different angle and the mechanism connecting the valveswith the shaft consists of a plurality of cams, said cam beingpositioned on the shaft in such angular relation as to cause some ofsaid valves to open upon the first oscillation of the rocker, to openother of said valves and close the first opened valves on the thirdoscillation of the rocker and to close the said other valves whilesimultaneously opening the first opened valves upon a further number ofoscillations of the rocker arm dependent upon the setting of themanually movable member.

9. In a timing unit, a main shaft, a rocker loosely mounted on saidshaft and carrying a working pawl, a setting arm loosely mounted on saidshaft and manually movable with respect to said rocker, a cam looselymounted on said shaft adjacent said setting arm, a counting pawl carriedby said cam, a gravity counterbalance on said `cam for holding said pawlin elevated position, a counting disk secured to said shaft and lying inthe path of said counting pawl, an operating disk secured to said shaftand lying in the path of the working pawl on the rocker, a projection onsaid setting arm for engaging said cam, and means carried by said rockerfor engaging said cam to cause said counting pawl to move with saidcounting disk.

l0. The device of claim 9 in which the rocker is a housing enclosing andprotecting said pawls, said disks, and said cam.

1l.. The device of claim 9 in which the rocker is a housing surroundingsaid disks and said cam and the setting arm is loosely mounted on themain shaft and extending within and outside of said rocker housing.

12. The device of claim 9 in which the operating disk has three teethspaced within an angle of less than 180, the counting pawl has a plu-Cil rality of teeth one of which is alined with one of the teeth on theoperating disk and the number of settings of the setting arm is suchthat the main shaft will make one complete cycle for a complete numberof oscillations of the rocker irrespective of its settings, the numberof such settings being in excess of four.

13. The device of claim 9 in which the operating disk has three teethspaced within an angle of 90c and the remaining 270Q of the operatingdisk is smooth, the teeth on the counting disk correspond with thesmooth periphery of the operating disk and the first tooth on thecounting disk corresponds with the third tooth on the operating diskwhereby the rst oscillation in any cycle irrespective of setting willadvance the shaft thru 90, the third oscillation of the rocker at anysetting will advance the shaft thru a second 90 and the remaining 180 oftravel will be caused by varying numbers of oscillations dependent uponthe setting of the setting arm.

14. In an interval control device, a timing unit, a valve controllingcam mechanism, a housingr for said timing unit, a two part housingsurrounding said cam mechanism, a single shaft passing through thetiming unit and the cam mechanism and journaled in said two parthousing, said shaft constituting the sole support for the timing unitand its housing, journals for said shaft separably carried by said twopart housing whereby removal of one part of the housing permits liftingof said shaft from the other part of the housing, said housings beingrelatively movable.

l5. In combination, an intermittently driven shaft, a bell crank shaftparallel thereto, a plurality cf cams angularly space-d about saiddriven shaft, a plurality of bell cranks independently movable on saidbell crank shaft for operation by said cams and a housing surroundingsaid bell cranks, said cams and said shafts, said housing including twodetachable sections separated horizontally in line with the axis of thedriven shaft, the lower section of said housing forming an oil reservoirin which the cams are emersed at each revolution of the driven shaft,said bell crank shaft being journaled in the upper section and removabletherewith to permit free access to and removal of the intermittentlydriven shaft.

16. A counterbalanced pawl carrier for a timing mechanism consisting ofa central portion having a circular recess therein for loosely mountingupon an operating shaft, a radial arm extending from said centralportion, a segmental countorbalance extending from said central portionat an obtuse angle from said radial arm and a counting pawl pivoted nearthe extremity of said radial arm.

17. The device of claim 16 plus a cylindrical member mounted coaxiallywith said pawl on said radial arm.

18. A counting pawl setting arm for a timing unit consisting of anelongated cylindrical member, a radial arm extending from one end ofsaid member and carrying a detent and a projection extending from themember diametrically and laterally opposite from said radial arm.

19. In a timing unit of the type adapted to be carried by the operatingshaft which it controls, a rocking housing having a central shaftrotatably mounted on said shaft, a sleeve rotatably mounted on saidshaft and rotatably projecting within said housing, a radial arm on saidsleeve extending parallel to one face of said housing, detent mechanismcarried in part by said housing and said arm, and a projection on saidsleeve extending inwardly within said housing beyond said sleeve.

20. In an interval control device, a timing unit, a plurality of valves,a valve controlling cam mechanism, a housing for said timing unit, ahousing for said valves, a housing for said cam mechanism supported onthe valve housing, and a single shaft passing thru the timing unit andthe cam mechanism, said timing unit and its housing being supportedsolely by said shaft, and said timing unit housing being movablerelative to the shaft and to the cam mechanism.

2l. In combination, a timing unit and a horizontal cam shaft operatedthereby, said unit being supported by the shaft, a housing for saidshaft comprising an upper part and a lower part joined together along ahorizontal plane thru the shaft axis, and a bell crank shaft in theupper part and journaled in the end walls thereof and carrying bellcranks in operative engagement with the cam shaft.

22. A cam shaft timer unit of the type adapted to be carried by the camshaft and forming a part of the linkage used for transmitting motion tothe cam shaft comprising a central shaft, a plurality of ratchet gearsmounted on the central shaft, a pawl arm loosely mounted on the shaftadjacent one of said gears, a pawl on said arm for engaging the teeth insaid one gear, gravity means tending to hold said arm in substantiallyupright position, a housing enclosing said gears and said arm andpivotally mounted on said central shaft, a pawl on the inner wall ofsaid housing for engaging the teeth of the other of said ratchet gears,a projection on said inner wall for engaging said arm, means foroscillating said housing thru a fixed arc, a setting arm pivotallymounted on said shaft and having adjustable engagement with said housingwhereby its arc of travel may be changed with respect to the arc oftravel of the housing and means rigidly connected to said setting armand having engagement with said pawl arm for changing the arc of travelof said arm with respect to the xed arc of travel of said housing.

23. The device of claim 22 in which said housing consists of two partsand in which the pawl on the inner wall is carried on one part and theprojection is carried on the other part, said other part whendisconnected from the one part being axially movable to expose the gearwheels and said pawl arm and said setting arm being axially movable withsaid other part.

CHARLES A. WARG.

